Explosively actuated power tool



Oct. 7, 1969 c. RossELsr ExPLosIvE'L'Y AcTuA'rED POWER 'roofJ 2 sheets-sheet 1 ruga ms. 2o. 196s f(llllrllllll.lll rllilllllllt INI IME l llllllllll il;

med veo. 20. 1966 2 Sheets-Sheet 2` nm y u .ak m x hx United States Patent F U.S. Cl. 227-10 3 Claims ABSTRACT OF THE DISCLOSURE A tool actuated by an explosive charge for driving fastening members. The forward portion is hinged to v facilitate the introduction of the fastening member in the tool. The fastening member serves to cause the driving piston rod to move rearwardly and eject a spent cartridge from the chamber to thereby facilitate reloading the tool.

The present invention relates to explosively actuated power tools. More particularly, it relates to power actuated apparatus for driving 'a fastening member of the class of plugs, bolts, points and other similar devices, into hard and compact material such as wood, cement, concrete, etc., by the action of a piston rod subjected to the thrust produced by the explosion of an explosive charge.

It is an object of the present invention to provide an improved explosively actuated driving tool which is easier and safer to operate.

A further object of the invention is to provide an explosively actuated driving tool adapted to cooperate with a fastening member so as to facilitate introduction vof the fastening member, ejection of a spent cartridge, and loading the tool.

In order that the invention may be more clearly understood, a preferred embodiment thereof is describedrbclow, purely by way of illustrative but nonlimiting example, with reference to the accompanying schematic drawings, in which:

FIG. 1 is a longitudinal section of a tool embodying the invention.

FIG. 2 is a plan view of a portion of the manipulating sleeve land taken at a right angle to the position of this sleeve in IFIG. 1.

FIG. 3 is a sectional view taken on the line III-Ill of FIG. 1.

FIG. 4 is an axial sectional view similar to FIG. 1 showing the position of the parts upon completion of the power stroke.

FIG. 5 in the left portion is a partial sectional view showing the hinged position of front part A relative to the rear part B and the portion shown at the right of the broken zone is Ian axial sectional view showing the elements rotated about the axis of tool ninety degrees from these elements as they appear in FIG. 1.

FIG. 6 is an axial sectional view showing the positions of the elements for ejection of a cartridge.

As is the case in certain known power actuated driving tools, the device is formed of two principal parts, namely 'a front part A connected to a rear part B. The rear part comprises a breech 1 to which is rigidly fixed a grip 2, provided with a trigger 3 intended toactuate a percussion mechanism contained in the breech 1 and of which the firing pin 4 is seen in FIG. 4.

A fork 5 is mounted on the breech 1 for limited sliding movement subject to the thrust of a safety spring 6 tending normally to maintain the cartridge C, out of reach of the aforesaid ring pin, as long las the front part A 3,471,074 Patented Oct. 7, 1969 of the tool is not thrust back towards the part B, by the application of the front end of the tool against the material in which the fastening member is to be driven.

On the fork 5 is hinged a barrel block 7 between branches 5a of this fork (FIG. 6). The barrel block 7 has 'an axial bore 8 of which the rear end opens into a loading chamber 9 intended to contain the cartridge C which, when the tool is ready for firing (FIG. 1), is locked in this chamber by the bridge 5b Iwhich connects the two vbranches 5w of the fork 5.

Towards the front, the barrel block 7 is extended by a cylindrical sleeve 7a forming one of the connecting members between the rear part B and the front part A of the tool.

The front part A includes la guide piece 10 rigidly xed to a tubular housing 10a which plays a triple role. It serves as a connecting member with the rear part B, as an expansion chamber for the propulsive gases arising from the explosive charge contained in the cartridge C, 'and as cylindrical guide for the middle part 11a of a piston rod 11. The pisotn rod has a rear part 11b guided in the bore 8 of the block 7, and a front part 11C guided in the posterior bore 12 of the guide piece 10. The expanding gases escape through orices 10b.

The guide piece 10 has in addition, beyond the posterior bore 12, an anterior bore 13 in which is guided a sliding and tilting barrel 14. The front end of the barrel 14 carries lan annular flange 15. The barrel 14 is mounted removably (for example by a pin 16) in a barrel holder 17 furnished with hinge pins 18. These pins extend respectively into stud holes 19 diametrically opposite one another and arranged in the front end of a manipulating sleeve 20 able to slide on the elements 7a and 10a. The holes 19 'are elongated as shown in FIG. 2 to accommodate a stroke for ejecting a spent cartridge C. The barrel holder 17 carries a positioning plate 21 arranged to be in contact (when the barrel 14 is -aligned with the axis of the tool) with the edges 20a of one of the two arms on the manipulating sleeve 20.

The piston rod carries Ia damper 22 intended to absorb the impact at the end of the travel of the piston rod upon the guide piece 10.

The recoil of the movable members with respect to the breech 1 is absorbed by a rear damper member 23 sliding in the breech, against the 'action of the safety spring 6. The damper member at the end of the back travel, abuts -against a shoulder 1a of the breech. The damper member 23 cooperates with the fork 5 by the intermediary of a spring 24 working in compression.

It will be noted that the barrel 14 and the bore 13 formed in the guide piece 10 are arranged in order that the tool can re plugs T (FIG. 5) of a well-known type. The head of the plug is furnished with a guiding portion G and an annular ange Ta at the rear end. To introduce the plug into the tool, the barrel 14 is made to pivot in such a way that its rear end is `accessible as shown in FIG. 5. After the plug is inserted in the bore 13 the plug is kept at this end of the barrel by its flange Ta.

lWhen the elements of the tool are in position shown in FIG. 5, a cartridge may be inserted in the chamber 9. If the chamber 9 is still occupied by spent cartridge the barrel 14 is hinged into alignment with the axis of the guide piece 10. The sleeve 20 is then moved towards the rear, which inserts the barrel 14 in the bore 13 of the guide piece 10.

The ange Ta prevents the plug from penetrating into the barrel 14, which makes the plug behave like a pusher with respect to the piston rod 11. The piston rod is thus urged rearwardly by such movement of the sleeve 20. At the end of the travel of this rearward movement of the sleeve thrust applied to the annular flange 15 produces a rearward movement of the piston rod and its lCe rear end penetrates slightly into the loading chamber 9 and causes the ejection of the spent cartridge.

A fresh cartridge may be inserted in the loading chamber 9 `and the parts hinged to bring them into alignment as shown in FIG. l. In this movement, the front surface of the bridge b urges the cartridge into proper seating `and serves as a breech plug for the loading chamber. The seating of the cartridge C serves to push the piston forwardly slightly. The tool is then ready for the fastening operation.

'For this operation, the tool is applied against the material M, at the point where the plug is to be driven and the front end of the apparatus is pressed rmly against the material M. The spring 6 allows a Slight rearward movement of the movable members of the tool with respect to the breech 1 to reduce to zero the Safety gap between the firing pin 4 and the cartridge C.

Manipulation of the trigger 3 then causes the explosion of the charge and the piston rod 11 is moved forward overcoming the resistance of the ange Ta. This ange shears and the piston rod thrusts the plug T, with sufficient energy to embed it into the material M.

It will be apparent that various changes and modifications may be incorporated without departing from the essential concept of the invention or the scope of the appended claims.

What I claim is:

1. An explosively actuated driving tool comprising a stock provided with a firing mechanism and trigger means, a connecting member attached to said stock and provided with an axial channel with a loading chamber arranged at the stock end of said member and intended to receive a cartridge, a guide piece connected to said connecting member `and having at least one longitudinal bore and a coaxial cylindrical passage, a sliding piston rod having two cylindrical parts between which is sittlated an intermediate part of greater diameter than said cylindrical parts, said intermediate part being guided in said bore, so that one of said cylindrical parts can penetrate into said axial channel of the connecting member, a manipulating sleeve having one end slidably mounted on said guide piece and a free end, a guide barrel adapted to receive a fastening member and the other cylindrical part of the piston rod, said guide barrel having one end hinged on said free end of the manipulating sleeve so that its other end can be brought, either into alignment with the axis of said guide piece to permit cooperation between the piston rod and the fastening member or, out of alignment, so as to be accessible and permit the introduction of the fastening member to be seated in the guide barrel.

2. A tool according to claim 1, in which the free end of the manipulating sleeve has on diametrically opposite sides, a pair of orifices elongated in the longitudinal direction of the sleeve, to receive the hinge of the guide barrel, in order that the said .guide barrel can slide longitudinally with respect to the manipulating sleeve.

3. A tool according to claim 1, in which the travel of the manipulating sleeve on the guide piece and the length of the piston rod are such that, when the guide barrel is aligned With the axis of the guide piece and when the manipulating sleeve is urged back in the direction of the stock, the piston rod is thrust back by the fastening member gripped in the guide barrel so as to eject the cartridge seated in the loading chamber.

References Cited UNITED STATES PATENTS 3,044,071 7/1962 Behrend 227-10 3,058,116 10/1-962 Hilti 227-10 3,239,121 3/1966 Kopf et al. 227-10 FOREIGN PATENTS l,l52,370 8/ 1963 Germany.

TRAVIS S. MCGEHEE, Primary Examiner 

